<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>WebSocket</title>
</head>
<body>
Welcome<br />
<input type="text" id="text"/>
<button onclick="send()">Send</button>
<button onclick="closeWebSocket()">Close</button>
<div id="message">
</div>

</body>

<script type="text/javascript">
    var websocket = null;
    //判断当前浏览器是否支持WebSocket
    if('WebSocket' in window){
        websocket = new WebSocket("ws://localhost:8080/socket/lily");
    }else{
        alert("Not support websocket");
    }

    //连接发生错误的回调方法
    websocket.onerror = function(){
        setMessageInnerHTML("error");
    }

    //连接成功建立的回调方法
    websocket.onopen = function (event){
        setMessageInnerHTML("open");
    }

    //接收消息的回调方法
    websocket.onmessage = function (event){
        setMessageInnerHTML(event.data);
    }

    //连接关闭的回调方法
    websocket.onclose = function(){
        setMessageInnerHTML("close");
    }

    /**
     * 监听窗口关闭事件，当窗口关闭时，主动去关闭websocket链接，防止链接还没断开就关闭窗口
     * server端会抛异常
     */
    window.onbeforeunload = function() {
        websocket.close();
    }

    //将消息显示在网页上
    function setMessageInnerHTML(innerHTML) {
        document.getElementById("message").innerHTML += innerHTML + '<br/>';
    }

    //关闭连接
    function closeWebSocket() {
        websocket.close();
    }

    //发送消息
    function send(){
        var message = document.getElementById('text').value;
        websocket.send(message);
    }
</script>
</html>